Re: debugging lack of link events

[Dan Williams <dcbw redhat com>]

On Wed, 2005-08-10 at 11:47 -0400, Derek Atkins wrote:
> Quoting Dan Williams <dcbw redhat com>:
> 
> > I'm looking at this too, my e1000 driver seems to take a _really_ long
> > time to notify the netlink socket that the device has changed status
> > (like 20s or so?).  That's not cool.  I'm attempting to distill a
> > testcase that I could send to kernel people, you might be able to use it
> > too to narrow the causes down.
> 
> Well, I do see the kernel log message almost immediately.  I haven't 
> looked into
> the kernel code-path between the link-up printk() and the netlink message.

Well, the kernel logs most likely come from
netif_carrier_on()/netif_carrier_off(), which the driver calls when it
knows that the link is either on or off.  That should queue up the
netlink message, but my guess is that something is getting lost of
delayed between the driver telling the kernel that the link has changed,
and the kernel writing that data to the userspace netlink socket that
HAL listens on.

Dan